| abstract |
ABSTRACT A multiple filter unit in the form of a complete interchangeable unit for insertion into a motor vehicle interior ventilation duct, or into the mouth of air conditioners or into suction-producing apparatus for closed environments, comprising a rigid casing provided with retention and sealing means, a series of filter elements and/or chemical products and/or electrostatic filtering devices disposed in a predetermined order for filtering solid particulate matter, mists and air pollutant gases, and means for checking the degree of efficiency. |